“We are very different on our approach to illegal immigration,” DeSantis said in an interview with conservative radio host John Fredericks.

The issue has been seen as a Republican primary weakness for Putnam who, as a member of Congress, took some votes seen by some in the party as supporting “amnesty.”

In the interview, DeSantis specifically pointed out Putnam’s support of legislation spearheaded by Sen. John McCain (R-Ariz.) that included a guest worker program for undocumented immigrants across all industries, and a separate 2013 bill authored by the bipartisan “Gang of Eight” that offered a pathway to citizenship. At that time, Putnam was the state’s agriculture commissioner, not a member of Congress. But he publicly supported the plan.

Putnam, whose campaign did not return a request seeking comment, has defended his record on immigration.

“Adam Putnam has a clear record against amnesty, against illegal immigration and against sanctuary cities,” Amanda Bevis, his campaign spokeswoman told the Tampa Bay Times earlier this month.

DeSantis said he disagrees with Putnam on the mandatory use of E-Verify, a program used to verify the legal status of those seeking work through a federal database. The issue in Florida does not fall along traditional party lines. The business community and sugar industry, both of whom support Putnam, oppose mandatory E-Verify because they fear it will crimp the flow of cheap labor.

“I support mandatory E-Verify. If you want to combat illegal immigration you’ve got to insist on having a legal workforce,” DeSantis said. “He opposes mandatory E-Verify.”

The GOP primary has so far been a largely quiet affair.

Putnam’s campaign has spent more than $3 million on TV ads, but those have largely been positive and biographical, while DeSantis, who currently has less money, has relied almost exclusively on appearances on Fox News and conservative radio to get his message out. He is a frequent “no comment” in stories about Florida issues and canceled a Palm Beach County forum appearance with Putnam.

The trend has not gone unnoticed.

“I don’t duck the media,” Putnam said during the Palm Beach forum. “If you can’t show up and answer tough questions from members of the media, how are you going to lead the third largest state in America?”